Application of AIM Parameters at Ring Critical Points for Estimation of π‐Electron Delocalization in Six‐Membered Aromatic and Quasi‐Aromatic Rings

Palusiak, Marcin; Krygowski, Tadeusz M.

doi:10.1002/chem.200700250

Cited by 160 publications

(141 citation statements)

References 117 publications

Supporting

Mentioning

134

Contrasting

Order By: Relevance

“…Clearly, the ٌ 2 values in the lithium bonding are larger than those in the hydrogen bonding. It is well proved that the magnitude of the electron density function estimated at BCP can reflect the strength of a given bond [38]. The ٌ 2 values in the lithium-bonded systems and hydrogen-bonded systems also support such conclusion.…”

Section: Aim Analysessupporting

confidence: 62%

Comparative study on the nonadditivity of methyl group in lithium bonding and hydrogen bonding

Cheng

Gong

et al. 2008

Int J of Quantum Chemistry

View full text Add to dashboard Cite

ABSTRACT:Quantum chemical calculations at the second-order Moeller-Plesset (MP2) level with 6-311ϩϩG(d,p) basis set have been performed on the lithium-bonded and hydrogen-bonded systems. The interaction energy, binding distance, bond length, and stretch frequency in these systems have been analyzed to study the nonadditivity of methyl group in the lithium bonding and hydrogen bonding. In the complexes involving with NH 3 , the introduction of one methyl group into NH 3 molecule results in an increase of the strength of lithium bonding and hydrogen bonding. The insertion of two methyl groups into NH 3 molecule also leads to an increase of the hydrogen bonding strength but a decrease of the lithium bonding strength relative to that of the first methyl group. The addition of three methyl groups into NH 3 molecule causes the strongest hydrogen bonding and the weakest lithium bonding. Although the presence of methyl group has a different influence on the lithium bonding and hydrogen bonding, a negative nonadditivity of methyl group is found in both interactions. The effect of methyl group on the lithium bonding and hydrogen bonding has also been investigated with the natural bond orbital and atoms in molecule analyses.

show abstract

Section: Aim Analysessupporting

confidence: 62%

Comparative study on the nonadditivity of methyl group in lithium bonding and hydrogen bonding

Cheng

Gong

et al. 2008

Int J of Quantum Chemistry

View full text Add to dashboard Cite

show abstract

“…The highest values for electron density in hydrogen bonding bond critical points (BCP) of III and IV follow the interaction energy [44,45]. The ability to form strong hydrogen bonds with an N-oxide group as a proton acceptor has been already reported by us on the basis of experimental research on pyridine N-oxides [17].…”

Section: Intramolecular Hydrogen Bondsmentioning

confidence: 92%

Non-covalent interactions of N-phenyl-1,5-dimethyl-1H-imidazole-4-carboxamide 3-oxide derivatives—a case of intramolecular N-oxide hydrogen bonds

et al. 2017

Self Cite

View full text Add to dashboard Cite

The crystal structures of new N-phenyl-1,5-dimethyl-1H-imidazole-4-carboxamide 3-oxide derivatives are reported. The results of X-ray diffraction showed the existence of intramolecular hydrogen bonding between carboxamide nitrogen donors and N-oxide oxygen acceptors. The use of Quantum Theory of Atoms in Molecules allowed its classification as a strong interaction, with energy about 10 kcal/mol, and of intermediate character between closed shell and shared bonds. Comparison of experimental data and quantum theoretical calculations indicated that a substituent attached to the phenyl ring in the para position influences the strength and geometry of the title hydrogen bonding. Stronger π-electronwithdrawing properties of the higher energy substituent of the intramolecular hydrogen bond are observed. Among other intermolecular contacts in the studied crystals are C-H…O/ C-H…N hydrogen bonds of imidazole carbon atoms and some π…π stacking interactions between aromatic molecular fragments. Their importance in stabilization of the crystal structure was confirmed by the results of Hirshfeld surface analysis.

show abstract

“…64 Ellipticity index of aromaticity (EL), 66 which measures bonding electron density deformations reflected in negative eigenvalues of the Hessian matrix of the electronic density in the bond critical point (BCP). Density of the total electron energy at the ring critical point (H RCP ), 67 which is one of the AIM parameters that has been proven to serve as a quantitative measure of aromaticity in a number of molecular rings. 68 Formal definitions of all the above listed indices can be found in the source papers as well as in the manual of the MultiWFN program, 69 which has been used to calculate HOMA (with parameters for the C-C bond calculated consistently according to ref.…”

Section: 16mentioning

confidence: 99%

The electron density of delocalized bonds (EDDB) applied for quantifying aromaticity

Szczepanik

Andrzejak

Dominikowska

et al. 2017

Phys. Chem. Chem. Phys.

164

145

View full text Add to dashboard Cite

In this study the recently developed electron density of delocalized bonds (EDDB) is used to define a new measure of aromaticity in molecular rings. The relationships between bond-length alternation, electron delocalization and diatropicity of the induced ring current are investigated for a test set of representative molecular rings by means of correlation and principal component analyses involving the most popular aromaticity descriptors based on structural, electronic, and magnetic criteria. Additionally, a qualitative comparison is made between EDDB and the magnetically induced ring-current density maps from the ipsocentric approach for a series of linear acenes. Special emphasis is given to the comparative study of the description of cyclic delocalization of electrons in a wide range of organic aromatics in terms of the kekulean multicenter index KMCI and the newly proposed EDDB k index.

show abstract

Application of AIM Parameters at Ring Critical Points for Estimation of π‐Electron Delocalization in Six‐Membered Aromatic and Quasi‐Aromatic Rings

Cited by 160 publications

References 117 publications

Comparative study on the nonadditivity of methyl group in lithium bonding and hydrogen bonding

Comparative study on the nonadditivity of methyl group in lithium bonding and hydrogen bonding

Non-covalent interactions of N-phenyl-1,5-dimethyl-1H-imidazole-4-carboxamide 3-oxide derivatives—a case of intramolecular N-oxide hydrogen bonds

The electron density of delocalized bonds (EDDB) applied for quantifying aromaticity

Contact Info

Product

Resources

About